At present, human beings not only have a high demand for appearance and quality of a product, but also pay more attention to the price and practicability of the product. In the display field, especially in the organic light-emitting diode (OLED) display field, due to factors such as the instability of a driving transistor and the aging of the OLED, for the same image data voltage, the currents flowing through the OLED are different at different times, so that the display panel has non-uniform brightness as a whole or presents ghost.